fix: fix padding.

demo/Ursa.Demo/Pages/IconButtonDemo.axaml

@@ -24,7 +24,10 @@
             IconPlacement="{Binding #placement.Value}"
             IsLoading="{Binding #loading.IsChecked}">
             <u:IconButton.Icon>
-                <TextBlock Text="🐼" HorizontalAlignment="Center" FontSize="40" />
+                <TextBlock
+                    HorizontalAlignment="Center"
+                    FontSize="40"
+                    Text="🐼" />
             </u:IconButton.Icon>
         </u:IconButton>
         <u:IconButton
@@ -90,5 +93,16 @@
                     Data="{StaticResource iconGlyph}" />
             </u:IconButton.Icon>
         </u:IconButton>
+        <u:IconButton
+            Classes="Danger"
+            IsLoading="{Binding #loading.IsChecked}"
+            Theme="{DynamicResource SolidIconButton}">
+            <u:IconButton.Icon>
+                <TextBlock
+                    HorizontalAlignment="Center"
+                    FontSize="40"
+                    Text="🐼" />
+            </u:IconButton.Icon>
+        </u:IconButton>
     </StackPanel>
 </UserControl>

src/Ursa.Themes.Semi/Controls/IconButton.axaml

@@ -38,8 +38,7 @@
                         RowDefinitions="Auto, Auto">
                         <Panel
                             Name="PART_IconRoot"
-                            Grid.Column="0"
+                            Grid.Column="0">
-                            Margin="0,0,8,0">
                             <Panel.IsVisible>
                                 <MultiBinding Converter="{x:Static BoolConverters.Or}">
                                     <Binding Path="IsLoading" RelativeSource="{RelativeSource TemplatedParent}" />
@@ -61,6 +60,7 @@
                         <ContentPresenter
                             Name="PART_ContentPresenter"
                             Grid.Column="1"
+                            Margin="8 0 0 0"
                             HorizontalAlignment="Center"
                             VerticalAlignment="Center"
                             Content="{TemplateBinding Content}" />
@@ -107,16 +107,20 @@
             <Setter Property="Background" Value="{DynamicResource ButtonDefaultDisabledBackground}" />
             <Setter Property="Foreground" Value="{DynamicResource ButtonDefaultDisabledForeground}" />
         </Style>
+        
+        <Style Selector="^:empty[IsLoading=False] /template/ ContentPresenter#PART_ContentPresenter">
+            <Setter Property="Margin" Value="0"></Setter>
+        </Style>
 
         <Style Selector="^:right">
             <Style Selector="^ /template/ Panel#PART_IconRoot">
                 <Setter Property="Grid.Column" Value="1" />
                 <Setter Property="Grid.Row" Value="0" />
-                <Setter Property="Margin" Value="8 0 0 0" />
             </Style>
             <Style Selector="^ /template/ ContentPresenter#PART_ContentPresenter">
                 <Setter Property="Grid.Column" Value="0" />
                 <Setter Property="Grid.Row" Value="0" />
+                <Setter Property="Margin" Value="0 0 8 0" />
             </Style>
         </Style>
 
@@ -124,11 +128,11 @@
             <Style Selector="^ /template/ Panel#PART_IconRoot">
                 <Setter Property="Grid.Column" Value="0" />
                 <Setter Property="Grid.Row" Value="0" />
-                <Setter Property="Margin" Value="0 0 8 0" />
             </Style>
             <Style Selector="^ /template/ ContentPresenter#PART_ContentPresenter">
                 <Setter Property="Grid.Column" Value="1" />
                 <Setter Property="Grid.Row" Value="0" />
+                <Setter Property="Margin" Value="8 0 0 0" />
             </Style>
         </Style>
 
@@ -136,11 +140,11 @@
             <Style Selector="^ /template/ Panel#PART_IconRoot">
                 <Setter Property="Grid.Column" Value="0" />
                 <Setter Property="Grid.Row" Value="0" />
-                <Setter Property="Margin" Value="0 0 0 4" />
             </Style>
             <Style Selector="^ /template/ ContentPresenter#PART_ContentPresenter">
                 <Setter Property="Grid.Column" Value="0" />
                 <Setter Property="Grid.Row" Value="1" />
+                <Setter Property="Margin" Value="0 4 0 0" />
             </Style>
         </Style>
 
@@ -148,11 +152,11 @@
             <Style Selector="^ /template/ Panel#PART_IconRoot">
                 <Setter Property="Grid.Column" Value="0" />
                 <Setter Property="Grid.Row" Value="1" />
-                <Setter Property="Margin" Value="0 4 0 0" />
             </Style>
             <Style Selector="^ /template/ ContentPresenter#PART_ContentPresenter">
                 <Setter Property="Grid.Column" Value="0" />
                 <Setter Property="Grid.Row" Value="0" />
+                <Setter Property="Margin" Value="0 0 0 4" />
             </Style>
         </Style>
 

src/Ursa/Controls/IconButton.cs

@@ -8,13 +8,14 @@ using Ursa.Common;
 
 namespace Ursa.Controls;
 
-[PseudoClasses(PC_Right, PC_Left, PC_Top, PC_Bottom)]
+[PseudoClasses(PC_Right, PC_Left, PC_Top, PC_Bottom, PC_Empty)]
 public class IconButton: Button
 {
     public const string PC_Right = ":right";
     public const string PC_Left = ":left";
     public const string PC_Top = ":top";
     public const string PC_Bottom = ":bottom";
+    public const string PC_Empty = ":empty";
     
     public static readonly StyledProperty<object?> IconProperty = AvaloniaProperty.Register<IconButton, object?>(
         nameof(Icon));
@@ -56,18 +57,32 @@ public class IconButton: Button
     {
         IconPlacementProperty.Changed.AddClassHandler<IconButton, IconPlacement>((o, e) =>
         {
-            o.SetPlacement(e.NewValue.Value);
+            o.SetPlacement(e.NewValue.Value, o.Icon);
+        });
+        IconProperty.Changed.AddClassHandler<IconButton, object?>((o, e) =>
+        {
+            o.SetPlacement(o.IconPlacement, e.NewValue.Value);
         });
     }
 
     protected override void OnApplyTemplate(TemplateAppliedEventArgs e)
     {
         base.OnApplyTemplate(e);
-        SetPlacement(IconPlacement);
+        SetPlacement(IconPlacement, Icon);
     }
 
-    private void SetPlacement(IconPlacement placement)
+    private void SetPlacement(IconPlacement placement, object? icon)
     {
+        if (icon is null)
+        {
+            PseudoClasses.Set(PC_Empty, true);
+            PseudoClasses.Set(PC_Left, false);
+            PseudoClasses.Set(PC_Right, false);
+            PseudoClasses.Set(PC_Top, false);
+            PseudoClasses.Set(PC_Bottom, false);
+            return;
+        }
+        PseudoClasses.Set(PC_Empty, false);
         PseudoClasses.Set(PC_Left, placement == IconPlacement.Left);
         PseudoClasses.Set(PC_Right, placement == IconPlacement.Right);
         PseudoClasses.Set(PC_Top, placement == IconPlacement.Top);